> -----Original Message-----
> From: Robin Murphy [mailto:robin.mur...@arm.com]
> Sent: 14 June 2021 12:23
> To: Shameerali Kolothum Thodi <shameerali.kolothum.th...@huawei.com>;
> linux-arm-ker...@lists.infradead.org; linux-a...@vger.kernel.org;
> iommu@lists.linux-foundation.org
> Cc: j...@solid-run.com; Linuxarm <linux...@huawei.com>;
> steven.pr...@arm.com; Guohanjun (Hanjun Guo) <guohan...@huawei.com>;
> yangyicong <yangyic...@huawei.com>; sami.muja...@arm.com;
> wanghuiqiang <wanghuiqi...@huawei.com>
> Subject: Re: [PATCH v5 3/8] ACPI/IORT: Add a helper to retrieve RMR memory
> regions
>
> On 2021-05-24 12:02, Shameer Kolothum wrote:
> > Add a helper function that retrieves RMR memory descriptors
> > associated with a given IOMMU. This will be used by IOMMU
> > drivers to setup necessary mappings.
> >
> > Now that we have this, invoke it from the generic helper
> > interface.
> >
> > Signed-off-by: Shameer Kolothum
> <shameerali.kolothum.th...@huawei.com>
> > ---
> > drivers/acpi/arm64/iort.c | 50
> +++++++++++++++++++++++++++++++++++++++
> > drivers/iommu/dma-iommu.c | 4 ++++
> > include/linux/acpi_iort.h | 7 ++++++
> > 3 files changed, 61 insertions(+)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index fea1ffaedf3b..01917caf58de 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -12,6 +12,7 @@
> >
> > #include <linux/acpi_iort.h>
> > #include <linux/bitfield.h>
> > +#include <linux/dma-iommu.h>
> > #include <linux/iommu.h>
> > #include <linux/kernel.h>
> > #include <linux/list.h>
> > @@ -837,6 +838,53 @@ static inline int iort_add_device_replay(struct
> device *dev)
> > return err;
> > }
> >
> > +/**
> > + * iort_iommu_get_rmrs - Helper to retrieve RMR info associated with
> IOMMU
> > + * @iommu: fwnode for the IOMMU
> > + * @head: RMR list head to be populated
> > + *
> > + * Returns: 0 on success, <0 failure
> > + */
> > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode,
> > + struct list_head *head)
> > +{
> > + struct iort_rmr_entry *e;
> > + struct acpi_iort_node *iommu;
> > + int rmrs = 0;
> > +
> > + iommu = iort_get_iort_node(iommu_fwnode);
> > + if (!iommu || list_empty(&iort_rmr_list))
> > + return -ENODEV;
> > +
> > + list_for_each_entry(e, &iort_rmr_list, list) {
> > + int prot = IOMMU_READ | IOMMU_WRITE | IOMMU_NOEXEC |
> IOMMU_MMIO;
> > + struct iommu_resv_region *region;
> > + enum iommu_resv_type type;
> > + struct acpi_iort_rmr_desc *rmr_desc;
> > +
> > + if (e->smmu != iommu)
> > + continue;
> > +
> > + rmr_desc = e->rmr_desc;
> > + if (e->flags & IOMMU_RMR_REMAP_PERMITTED)
> > + type = IOMMU_RESV_DIRECT_RELAXABLE;
> > + else
> > + type = IOMMU_RESV_DIRECT;
>
> Wasn't the idea that we can do all this during the initial parsing, i.e.
> we don't even have iort_rmr_entry, we store them as iommu_resv_regions
> and simply kmemdup() or whatever at this point?
Hmm... Not yet. I removed struct iommu_rmr() from v4. But yes, it looks like
we can get rid of iort_rmr_entry as well. Will give it a go in next.
Thanks,
Shameer
> Robin.
>
> > +
> > + region = iommu_alloc_resv_region(rmr_desc->base_address,
> > + rmr_desc->length,
> > + prot, type);
> > + if (region) {
> > + region->fw_data.rmr.flags = e->flags;
> > + region->fw_data.rmr.sid = e->sid;
> > + list_add_tail(®ion->list, head);
> > + rmrs++;
> > + }
> > + }
> > +
> > + return (rmrs == 0) ? -ENODEV : 0;
> > +}
> > +
> > /**
> > * iort_iommu_msi_get_resv_regions - Reserved region driver helper
> > * @dev: Device from iommu_get_resv_regions()
> > @@ -1108,6 +1156,8 @@ int iort_iommu_msi_get_resv_regions(struct
> device *dev, struct list_head *head)
> > const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
> > const u32 *input_id)
> > { return NULL; }
> > +int iort_iommu_get_rmrs(struct fwnode_handle *fwnode, struct list_head
> *head)
> > +{ return -ENODEV; }
> > #endif
> >
> > static int nc_dma_get_range(struct device *dev, u64 *size)
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index 229ec65d98be..f893d460cfa4 100644
> > --- a/drivers/iommu/dma-iommu.c
> > +++ b/drivers/iommu/dma-iommu.c
> > @@ -185,6 +185,9 @@ EXPORT_SYMBOL(iommu_put_dma_cookie);
> > int iommu_dma_get_rmrs(struct fwnode_handle *iommu_fwnode,
> > struct list_head *list)
> > {
> > + if (!is_of_node(iommu_fwnode))
> > + return iort_iommu_get_rmrs(iommu_fwnode, list);
> > +
> > return -EINVAL;
> > }
> > EXPORT_SYMBOL(iommu_dma_get_rmrs);
> > @@ -200,6 +203,7 @@ EXPORT_SYMBOL(iommu_dma_get_rmrs);
> > void iommu_dma_put_rmrs(struct fwnode_handle *iommu_fwnode,
> > struct list_head *list)
> > {
> > + generic_iommu_put_resv_regions(iommu_fwnode->dev, list);
> > }
> > EXPORT_SYMBOL(iommu_dma_put_rmrs);
> >
> > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> > index 1a12baa58e40..e8c45fa59531 100644
> > --- a/include/linux/acpi_iort.h
> > +++ b/include/linux/acpi_iort.h
> > @@ -39,6 +39,8 @@ const struct iommu_ops
> *iort_iommu_configure_id(struct device *dev,
> > const u32 *id_in);
> > int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head
> *head);
> > phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
> > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode,
> > + struct list_head *list);
> > #else
> > static inline void acpi_iort_init(void) { }
> > static inline u32 iort_msi_map_id(struct device *dev, u32 id)
> > @@ -59,6 +61,11 @@ int iort_iommu_msi_get_resv_regions(struct device
> *dev, struct list_head *head)
> >
> > static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void)
> > { return PHYS_ADDR_MAX; }
> > +
> > +static inline
> > +int iort_iommu_get_rmrs(struct fwnode_handle *iommu_fwnode,
> > + struct list_head *list)
> > +{ return -ENODEV; }
> > #endif
> >
> > #endif /* __ACPI_IORT_H__ */
> >
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